1. Field of the Invention
The present invention relates to an electronic counter for electric digital pulses having a counter chain which is to be controlled by way of pulses applied to a counting input and consisting of flip-flop cells which are identical to one another, and more particularly to a counter in which at least one change of the operating state of a first flip-flop cell into the respectively other operating state occurs in response to each counting pulse and in which, moreover, at every second change of the operating state of the individual flip-flop cells a simultaneous change of the operating state of at least one of the subsequently connected flip-flop cells occurs.
The invention also relates to a counter of the type set forth above in which a resetting of the operating states of all flip-flop cells of the counter is provided to reset the counter to ZERO, and a transfer circuit is provided between two successive flip-flop cells to determine the counting direction and includes a control input for receiving control signals.
2. Description of the Prior Art
Counters of the general type set forth above are known in the art as asychronous forward-backward counters and are described, for example, by Dieter Ulrich in his book Grundlagen der Digital-Elektronik und Digitalen Rechentechnik, Second Edition, Munich, 1975, p. 176. In this prior counter, the transfer circuit consists of an interconnection of a plurality of simple logic gates, by means of which the two outputs of a flip-flop cell and the two inputs of the subsequently connected flip-flop cell assigned thereto are connected with one another and which, in turn, is provided with an additional control input. For example, the transfer circuit can be embodied as illustrated in FIGS. 1 and 2, as will be discussed in greater detail below.
A disadvantage of such a construction of the transfer circuit, however, is that a representation in monolithically integrated counters require a great deal of space on the semiconductor chip and, moreover, notably increases the energy consumption of the counter.